It's actually really not very hard at all, but if you've never done it before, take it to a tech. And then ask him to show you how to do it so you don't have to do it again.
If you really want to try it yourself (which I don't reccomend if you've never done it before) here are some instructions:
Turning the key to the right tightens the neck, thus increasing forward bow.
Turning it to the left loosens it, increasing backbow.
Turn the key ONLY A QUARTER TURN at a time in the proper direction (based on the current bow of your neck). If there is resistance, DON'T force it - take it to a tech if you can't get it yourself. DON'T MAKE LARGE ADJUSTMENTS AT ONE TIME. YOU WILL DESTROY YOUR NECK. Always allow the neck to set for at least a half hour between adjustments, and don't overadjust. Usually one or two quarter turns is enough. Also keep in mind that you don't want your neck to be perfectly straight - a little bit of forward bow is normal, and actually makes the guitar a bit easier to play and improves action and intonation. After adjusting your truss rod, and after you've let it set and you are happy with your adjustments, tune your guitar and INTONATE it. This is so important, especially if you ever want to record in a studio.
To set your intonation, tune each string to a tuner, and then check the 12th fret (of each string). The 12th fret should match the pitch of the open string *always use a tuner for this*
If the note fretted at the 12th fret differs from the open string, adjust the bridge as follows: If the note is sharp, move the bridge saddle BACK a tiny bit. If the note is flat, move the string saddle FORWARD a tiny bit.
Post if you have any more questions about guitar maintenance.
[This message has been edited by powertickle (edited March 23, 2004).]
[This message has been edited by powertickle (edited March 23, 2004).]